1. Field of the Invention
The present invention relates to a painting type magnetic recording medium including a magnetic layer containing magnetic powder of iron nitride material and, particularly, to a magnetic recording medium realizing a high electromagnetic conversion characteristics and reliability.
2. Description of the Related Art
In order to realize a high recording density of a magnetic recording medium, an improvement of a magnetic characteristics of a magnetic layer of the magnetic recording medium, which is provided by painting of magnetic material on a base material of the magnetic recording medium, has been tried. In order to improve the magnetic characteristics of the painted magnetic layer, it has been known to use magnetic material having high magnetic characteristics as magnetic powder constituting the painted magnetic layer.
Since magnetic attractive force of particles of the powder having high magnetic characteristics, particularly, large saturation magnetization, is large and magnetic particles are attracted to each other, it is difficult to uniformly disperse the magnetic powder during a preparing step of a magnetic paint (powder dispersion step). The higher the dispersion of magnetic particles in the magnetic paint results in the higher the magnetic characteristics of a resultant magnetic recording medium, the higher the reproduced output and the lower the noise level of the output. Further, since the adsorbance of resin on magnetic particle surface is improved by improving the dispersion of the magnetic powder, a mechanical strength of the magnetic paint layer increases and the reliability is improved. Although it is confirmed that the improvement of the dispersion of magnetic powder having high magnetic characteristics improves both the electromagnetic conversion characteristics and the reliability of the final magnetic recording medium, there is no magnetic recording medium satisfying the required dispersion of magnetic powder as yet.